1. Field of the Invention
The present invention relates to a fuel injection valve that is utilized for supplying a fuel, for example, to the internal combustion engine of a vehicle.
2. Description of the Related Art
In recent years, while the regulation on exhaust gas of a vehicle or the like has been tightened, it has been required to atomize fuel spray injected from a fuel injection valve. In particular, with regard to the atomization of fuel spray, various kinds of studies have been made; for example, Patent Document 1 discloses a fuel injection valve whose injection hole inlet and injection hole outlet are made elliptical and slit-shaped, respectively, so that a uniform liquid film is formed and hence the atomization is facilitated.
Each of Patent Documents 2 and 3 discloses a fuel injection valve whose injection hole is made taper-shaped so that the atomization of fuel is facilitated.
Furthermore, Patent Document 4 discloses a fuel injection valve in which there are formed the respective concavees corresponding to the injection hole outlets of injection holes formed in an injection hole plate and each injection hole is formed in such a way as to step over the bottom plain of the concave so that the atomization is facilitated.